This patch adds support the the JESD216B standard and parse the SFDP
tables to dynamically initialize the spi_nor_basic_flash_parameter
structure.

Signed-off-by: Cyrille Pitchen <cyrille.pitc...@atmel.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 468 +++++++++++++++++++++++++++++++++++++++++-
 include/linux/mtd/spi-nor.h   |   6 +
 2 files changed, 473 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index a06fcf400b39..7fc0138c1d68 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -17,6 +17,7 @@
 #include <linux/mutex.h>
 #include <linux/math64.h>
 #include <linux/sizes.h>
+#include <linux/slab.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/of_platform.h>
@@ -79,6 +80,7 @@ struct flash_info {
                                         * Use dedicated 4byte address op codes
                                         * to support memory size above 128Mib.
                                         */
+#define SPI_NOR_SKIP_SFDP      BIT(11) /* Skip read of SFDP tables */
 };
 
 #define JEDEC_MFR(info)        ((info)->id[0])
@@ -1331,6 +1333,99 @@ static int spansion_quad_enable(struct spi_nor *nor)
        return 0;
 }
 
+static int spansion_new_quad_enable(struct spi_nor *nor)
+{
+       u8 sr_cr[2];
+       int ret;
+
+       /* Check current Quad Enable bit value. */
+       ret = read_cr(nor);
+       if (ret < 0) {
+               dev_err(nor->dev,
+                       "error while reading configuration register\n");
+               return -EINVAL;
+       }
+       sr_cr[1] = ret;
+       if (sr_cr[1] & CR_QUAD_EN_SPAN)
+               return 0;
+
+       dev_info(nor->dev, "setting Spansion Quad Enable (non-volatile) bit\n");
+
+       /* Keep the current value of the Status Register. */
+       ret = read_sr(nor);
+       if (ret < 0) {
+               dev_err(nor->dev,
+                       "error while reading status register\n");
+               return -EINVAL;
+       }
+       sr_cr[0] = ret;
+       sr_cr[1] |= CR_QUAD_EN_SPAN;
+
+       write_enable(nor);
+
+       ret = nor->write_reg(nor, SPINOR_OP_WRSR, sr_cr, 2);
+       if (ret < 0) {
+               dev_err(nor->dev,
+                       "error while writing configuration register\n");
+               return -EINVAL;
+       }
+
+       ret = spi_nor_wait_till_ready(nor);
+       if (ret < 0) {
+               dev_err(nor->dev, "error while waiting for WRSR completion\n");
+               return ret;
+       }
+
+       /* read back and check it */
+       ret = read_cr(nor);
+       if (!(ret > 0 && (ret & CR_QUAD_EN_SPAN))) {
+               dev_err(nor->dev, "Spansion Quad bit not set\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int sr2_bit7_quad_enable(struct spi_nor *nor)
+{
+       u8 sr2;
+       int ret;
+
+       /* Check current Quad Enable bit value. */
+       ret = nor->read_reg(nor, SPINOR_OP_RDSR2, &sr2, 1);
+       if (ret)
+               return ret;
+       if (sr2 & SR2_QUAD_EN_BIT7)
+               return 0;
+
+       /* Update the Quad Enable bit. */
+       sr2 |= SR2_QUAD_EN_BIT7;
+
+       write_enable(nor);
+
+       ret = nor->write_reg(nor, SPINOR_OP_WRSR2, &sr2, 1);
+       if (ret < 0) {
+               dev_err(nor->dev,
+                       "error while writing status register 2\n");
+               return -EINVAL;
+       }
+
+       ret = spi_nor_wait_till_ready(nor);
+       if (ret < 0) {
+               dev_err(nor->dev, "error while waiting for WRSR2 completion\n");
+               return ret;
+       }
+
+       /* Read back and check it. */
+       ret = nor->read_reg(nor, SPINOR_OP_RDSR2, &sr2, 1);
+       if (ret || !(sr2 & SR2_QUAD_EN_BIT7)) {
+               dev_err(nor->dev, "SR2 Quad bit not set\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 static int spi_nor_check(struct spi_nor *nor)
 {
        if (!nor->dev || !nor->read || !nor->write ||
@@ -1359,11 +1454,381 @@ static inline void spi_nor_set_erase_settings(struct 
spi_nor_erase_type *erase,
        erase->opcode = opcode;
 }
 
+static int spi_nor_read_sfdp(struct spi_nor *nor, u32 addr,
+                            size_t len, void *buf)
+{
+       u8 addr_width, read_opcode, read_dummy;
+       int ret;
+
+       read_opcode = nor->read_opcode;
+       addr_width = nor->addr_width;
+       read_dummy = nor->read_dummy;
+
+       nor->read_opcode = SPINOR_OP_RDSFDP;
+       nor->addr_width = 3;
+       nor->read_dummy = 8;
+
+       ret = nor->read(nor, addr, len, (u8 *)buf);
+
+       nor->read_opcode = read_opcode;
+       nor->addr_width = addr_width;
+       nor->read_dummy = read_dummy;
+
+       return (ret < 0) ? ret : 0;
+}
+
+struct sfdp_parameter_header {
+       u8              id_lsb;
+       u8              minor;
+       u8              major;
+       u8              length; /* in double words */
+       u8              parameter_table_pointer[3]; /* byte address */
+       u8              id_msb;
+};
+
+#define SFDP_PARAM_HEADER_ID(p)        ((u16)(((p)->id_msb << 8) | 
(p)->id_lsb))
+#define SFDP_PARAM_HEADER_PTP(p) \
+       ((u32)(((p)->parameter_table_pointer[2] << 16) | \
+              ((p)->parameter_table_pointer[1] <<  8) | \
+              ((p)->parameter_table_pointer[0] <<  0)))
+
+
+#define SFDP_BFPT_ID           0xff00u /* Basic Flash Parameter Table */
+
+#define SFDP_SIGNATURE         0x50444653u
+#define SFDP_JESD216_MAJOR     1
+#define SFDP_JESD216_MINOR     0
+#define SFDP_JESD216A_MINOR    5
+#define SFDP_JESD216B_MINOR    6
+
+struct sfdp_header {
+       u32             signature; /* Ox50444653 <=> "SFDP" */
+       u8              minor;
+       u8              major;
+       u8              nph; /* 0-base number of parameter headers */
+       u8              unused;
+
+       /* Basic Flash Parameter Table. */
+       struct sfdp_parameter_header    bfpt_header;
+};
+
+/* Basic Flash Parameter Table */
+
+/* 1st DWORD. */
+#define BFPT_WORD0_FAST_READ_1_1_2     BIT(16)
+#define BFPT_WORD0_ADDRESS_BYTES_MASK  GENMASK(18, 17)
+#define BFPT_WORD0_ADDRESS_BYTES_3_ONLY        (0u << 17)
+#define BFPT_WORD0_ADDRESS_BYTES_3_OR_4        (1u << 17)
+#define BFPT_WORD0_ADDRESS_BYTES_4_ONLY        (2u << 17)
+#define BFPT_WORD0_DTR                 BIT(19)
+#define BFPT_WORD0_FAST_READ_1_2_2     BIT(20)
+#define BFPT_WORD0_FAST_READ_1_4_4     BIT(21)
+#define BFPT_WORD0_FAST_READ_1_1_4     BIT(22)
+
+/* 15th DWORD. */
+
+/*
+ * (from JESD216B)
+ * Quad Enable Requirements (QER):
+ * - 000b: Device does not have a QE bit. Device detects 1-1-4 and 1-4-4
+ *         reads based on instruction. DQ3/HOLD# functions are hold during
+ *         instruction pahse.
+ * - 001b: QE is bit 1 of status register 2. It is set via Write Status with
+ *         two data bytes where bit 1 of the second byte is one.
+ *         [...]
+ *         Writing only one byte to the status register has the side-effect of
+ *         clearing status register 2, including the QE bit. The 100b code is
+ *         used if writing one byte to the status register does not modify
+ *         status register 2.
+ * - 010b: QE is bit 6 of status register 1. It is set via Write Status with
+ *         one data byte where bit 6 is one.
+ *         [...]
+ * - 011b: QE is bit 7 of status register 2. It is set via Write status
+ *         register 2 instruction 3Eh with one data byte where bit 7 is one.
+ *         [...]
+ *         The status register 2 is read using instruction 3Fh.
+ * - 100b: QE is bit 1 of status register 2. It is set via Write Status with
+ *         two data bytes where bit 1 of the second byte is one.
+ *         [...]
+ *         In contrast to the 001b code, writing one byte to the status
+ *         register does not modify status register 2.
+ * - 101b: QE is bit 1 of status register 2. Status register 1 is read using
+ *         Read Status instruction 05h. Status register2 is read using
+ *         instruction 35h. QE is set via Writ Status instruction 01h with
+ *         two data bytes where bit 1 of the second byte is one.
+ *         [...]
+ */
+#define BFPT_WORD14_QER_MASK           GENMASK(22, 20)
+#define BFPT_WORD14_QER_NONE           (0 << 20) /* Micron */
+#define BFPT_WORD14_QER_SR2_BIT1_BUGGY (1 << 20)
+#define BFPT_WORD14_QER_SR1_BIT6       (2 << 20) /* Macronix */
+#define BFPT_WORD14_QER_SR2_BIT7       (3 << 20)
+#define BFPT_WORD14_QER_SR2_BIT1_NO_RD (4 << 20)
+#define BFPT_WORD14_QER_SR2_BIT1       (5 << 20) /* Spansion */
+
+/* JESD216B defines a Basic Flash Parameter Table of 16 words. */
+#define SFDP_BFPT_MAX_WORDS    16
+
+struct sfdp_bfpt {
+       u32     word[SFDP_BFPT_MAX_WORDS];
+};
+
+/* Fast Read settings. */
+#define BFPT_FAST_READ_WAIT_STATES(half)       ((((u16)(half)) >> 0) & 0x1f)
+#define BFPT_FAST_READ_MODE_CLOCKS(half)       ((((u16)(half)) >> 5) & 0x07)
+#define BFPT_FAST_READ_OP_CODE(half)           ((((u16)(half)) >> 8) & 0xff)
+
+struct sfdp_read {
+       /* The protocol index of SPI x-y-z. */
+       enum spi_nor_protocol_index     pindex;
+
+       /*
+        * The bit <wbit> in DWORD<windex> tells us whether the
+        * Fast Read x-y-z command is supported.
+        */
+       int                             windex;
+       int                             wbit;
+
+       /*
+        * The half-word at offset <hshift> in DWORD<hindex> encodes the
+        * op code, the number of mode clocks and the number of wait states
+        * to be used by Fast Read x-y-z commands.
+        */
+       int                             hindex;
+       int                             hshift;
+};
+
+static const struct sfdp_read sfdp_reads[] = {
+       /* Supported: DWORD0 bit 16,  Settings: DWORD3 bit[15:0] */
+       {SNOR_PINDEX_1_1_2, 0, 16, 3,  0},
+
+       /* Supported: DWORD0 bit 20,  Settings: DWORD3 bit[31:16] */
+       {SNOR_PINDEX_1_2_2, 0, 20, 3, 16},
+
+       /* Supported: DWORD4 bit  0,  Settings: DWORD5 bit[31:16] */
+       {SNOR_PINDEX_2_2_2, 4,  0, 5, 16},
+
+       /* Supported: DWORD0 bit 22,  Settings: DWORD2 bit[31:16] */
+       {SNOR_PINDEX_1_1_4, 0, 22, 2, 16},
+
+       /* Supported: DWORD0 bit 21,  Settings: DWORD2 bit[15:0] */
+       {SNOR_PINDEX_1_4_4, 0, 21, 2, 0},
+
+       /* Supported: DWORD4 bit  4,  Settings: DWORD6 bit[31:16] */
+       {SNOR_PINDEX_4_4_4, 4, 4, 6, 16},
+};
+
+
+/* Sector Erase settings. */
+#define BFPT_ERASE_SIZE(half)          ((((u16)(half)) >> 0) & 0xff)
+#define BFPT_ERASE_OP_CODE(half)       ((((u16)(half)) >> 8) & 0xff)
+
+struct sfdp_erase {
+       /*
+        * The half-word at offset <hshift> in DWORD<hindex> encodes the
+        * op code and erase sector size to be used by Sector Erase commands.
+        */
+       int             hindex;
+       int             hshift;
+};
+
+static const struct sfdp_erase sfdp_erases[SNOR_MAX_ERASE_TYPES] = {
+       /* Erase Type 1 in DWORD7 bits[15:0] */
+       {7, 0},
+
+       /* Erase Type 2 in DWORD7 bits[31:16] */
+       {7, 16},
+
+       /* Erase Type 3 in DWORD8 bits[15:0] */
+       {8, 0},
+
+       /* Erase Type 4: in DWORD8 bits[31:16] */
+       {8, 16},
+};
+
+
+static int spi_nor_parse_bfpt(struct spi_nor *nor,
+                             const struct sfdp_parameter_header *bfpt_header,
+                             struct spi_nor_basic_flash_parameter *params)
+{
+       struct sfdp_bfpt bfpt;
+       size_t len;
+       int i, err;
+       u32 addr;
+       u16 half;
+
+       /* JESD216 Basic Flash Parameter Table length is at least 9 words. */
+       if (bfpt_header->length < 9)
+               return -EINVAL;
+
+       /* Read the Basic Flash Parameter Table. */
+       len = min_t(size_t, sizeof(bfpt),
+                   bfpt_header->length * sizeof(uint32_t));
+       addr = SFDP_PARAM_HEADER_PTP(bfpt_header);
+       memset(&bfpt, 0, sizeof(bfpt));
+       err = spi_nor_read_sfdp(nor,  addr, len, &bfpt);
+       if (err)
+               return err;
+
+       for (i = 0; i < SFDP_BFPT_MAX_WORDS; ++i)
+               bfpt.word[i] = le32_to_cpu(bfpt.word[i]);
+
+       memset(params, 0, sizeof(*params));
+
+       /* Fast Read settings. */
+       params->rd_modes = (SNOR_MODE_SLOW | SNOR_MODE_1_1_1);
+       spi_nor_set_read_settings(&params->reads[SNOR_PINDEX_SLOW],
+                                 0, 0, SPINOR_OP_READ);
+       spi_nor_set_read_settings(&params->reads[SNOR_PINDEX_1_1_1],
+                                 0, 8, SPINOR_OP_READ_FAST);
+
+       for (i = 0; i < ARRAY_SIZE(sfdp_reads); ++i) {
+               const struct sfdp_read *rd_info = &sfdp_reads[i];
+               struct spi_nor_read *read = &params->reads[rd_info->pindex];
+
+               if (!(bfpt.word[rd_info->windex] & BIT(rd_info->wbit)))
+                       continue;
+
+               params->rd_modes |= BIT(rd_info->pindex);
+               half = bfpt.word[rd_info->hindex] >> rd_info->hshift;
+               read->num_mode_clocks = BFPT_FAST_READ_MODE_CLOCKS(half);
+               read->num_wait_states = BFPT_FAST_READ_WAIT_STATES(half);
+               read->opcode = BFPT_FAST_READ_OP_CODE(half);
+       }
+
+       /* Page Program settings. */
+       params->wr_modes = SNOR_MODE_1_1_1;
+       params->page_programs[SNOR_PINDEX_1_1_1] = SPINOR_OP_PP;
+
+       /* Sector Erase settings. */
+       for (i = 0; i < SNOR_MAX_ERASE_TYPES; ++i) {
+               const struct sfdp_erase *er_info = &sfdp_erases[i];
+               struct spi_nor_erase_type *erase = &params->erase_types[i];
+
+               half = bfpt.word[er_info->hindex] >> er_info->hshift;
+               erase->size = BFPT_ERASE_SIZE(half);
+               erase->opcode = BFPT_ERASE_OP_CODE(half);
+       }
+
+       /* Stop here if not JESD216 rev A or later. */
+       if (bfpt_header->length < 15)
+               return 0;
+
+       /* Enable Quad I/O. */
+       switch (bfpt.word[14] & BFPT_WORD14_QER_MASK) {
+       default:
+       case BFPT_WORD14_QER_NONE:
+               break;
+
+       case BFPT_WORD14_QER_SR2_BIT1_BUGGY:
+       case BFPT_WORD14_QER_SR2_BIT1_NO_RD:
+               params->enable_quad_io = spansion_quad_enable;
+               break;
+
+       case BFPT_WORD14_QER_SR1_BIT6:
+               params->enable_quad_io = macronix_quad_enable;
+               break;
+
+       case BFPT_WORD14_QER_SR2_BIT7:
+               params->enable_quad_io = sr2_bit7_quad_enable;
+               break;
+
+       case BFPT_WORD14_QER_SR2_BIT1:
+               params->enable_quad_io = spansion_new_quad_enable;
+               break;
+       }
+
+       return 0;
+}
+
+static int spi_nor_parse_sfdp(struct spi_nor *nor,
+                             struct spi_nor_basic_flash_parameter *params)
+{
+       const struct sfdp_parameter_header *param_header, *bfpt_header;
+       struct sfdp_parameter_header *param_headers = NULL;
+       struct sfdp_header header;
+       size_t psize;
+       int i, err;
+
+       /* Get the SFDP header. */
+       err = spi_nor_read_sfdp(nor, 0, sizeof(header), &header);
+       if (err)
+               return err;
+
+       /* Check the SFDP header version. */
+       if (le32_to_cpu(header.signature) != SFDP_SIGNATURE ||
+           header.major != SFDP_JESD216_MAJOR ||
+           header.minor < SFDP_JESD216_MINOR)
+               return -EINVAL;
+
+       /*
+        * Verify that the first and only mandatory parameter header is a
+        * Basic Flash Parameter Table header as specified in JESD216.
+        */
+       bfpt_header = &header.bfpt_header;
+       if (SFDP_PARAM_HEADER_ID(bfpt_header) != SFDP_BFPT_ID ||
+           bfpt_header->major != SFDP_JESD216_MAJOR)
+               return -EINVAL;
+
+       /* Allocate memory for parameter headers. */
+       if (header.nph) {
+               psize = header.nph * sizeof(*param_headers);
+
+               param_headers = kmalloc(psize, GFP_KERNEL);
+               if (!param_headers) {
+                       dev_err(nor->dev,
+                               "failed to allocate memory for SFDP parameter 
headers\n");
+                       return -ENOMEM;
+               }
+
+               err = spi_nor_read_sfdp(nor, sizeof(header),
+                                       psize, param_headers);
+               if (err) {
+                       dev_err(nor->dev,
+                               "failed to read SFDP parameter headers\n");
+                       goto exit;
+               }
+       }
+
+       /*
+        * Check other parameter headers to get the latest revision of
+        * the basic flash parameter table.
+        */
+       for (i = 0; i < header.nph; ++i) {
+               param_header = &param_headers[i];
+
+               if (SFDP_PARAM_HEADER_ID(param_header) == SFDP_BFPT_ID &&
+                   param_header->major == SFDP_JESD216_MAJOR &&
+                   (param_header->minor > bfpt_header->minor ||
+                    (param_header->minor == bfpt_header->minor &&
+                     param_header->length > bfpt_header->length)))
+                       bfpt_header = param_header;
+       }
+       err = spi_nor_parse_bfpt(nor, bfpt_header, params);
+       if (err)
+               goto exit;
+
+exit:
+       kfree(param_headers);
+       return (err) ? err : bfpt_header->minor;
+}
+
 static int spi_nor_init_params(struct spi_nor *nor,
                               const struct flash_info *info,
                               struct spi_nor_basic_flash_parameter *params)
 {
-       // TODO: parse SFDP table
+       int jesd216_minor = -EINVAL;
+
+       /* First trying to parse SFDP tables. */
+       if (!(info->flags & SPI_NOR_SKIP_SFDP)) {
+               jesd216_minor = spi_nor_parse_sfdp(nor, params);
+
+               if (jesd216_minor >= SFDP_JESD216A_MINOR)
+                       return 0;
+
+               if (jesd216_minor >= SFDP_JESD216_MINOR)
+                       goto set_enable_quad_io;
+       }
 
        /* If SFDP tables are not available, use legacy settings. */
        memset(params, 0, sizeof(*params));
@@ -1402,6 +1867,7 @@ static int spi_nor_init_params(struct spi_nor *nor,
                spi_nor_set_erase_settings(&params->erase_types[1],
                                           SNOR_ERASE_4K, SPINOR_OP_BE_4K_PMC);
 
+set_enable_quad_io:
        /* Select the procedure to set the Quad Enable bit. */
        if (params->rd_modes & (SNOR_MODE_1_1_4 |
                                SNOR_MODE_1_4_4 |
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 88ac446b1230..8fd9619dabff 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -41,6 +41,8 @@
 #define SPINOR_OP_WREN         0x06    /* Write enable */
 #define SPINOR_OP_RDSR         0x05    /* Read status register */
 #define SPINOR_OP_WRSR         0x01    /* Write status register 1 byte */
+#define SPINOR_OP_RDSR2                0x3f    /* Read status register 2 */
+#define SPINOR_OP_WRSR2                0x3e    /* Write status register 2 */
 #define SPINOR_OP_READ         0x03    /* Read data bytes (low frequency) */
 #define SPINOR_OP_READ_FAST    0x0b    /* Read data bytes (high frequency) */
 #define SPINOR_OP_READ_1_1_2   0x3b    /* Read data bytes (Dual Output SPI) */
@@ -56,6 +58,7 @@
 #define SPINOR_OP_CHIP_ERASE   0xc7    /* Erase whole flash chip */
 #define SPINOR_OP_SE           0xd8    /* Sector erase (usually 64KiB) */
 #define SPINOR_OP_RDID         0x9f    /* Read JEDEC ID */
+#define SPINOR_OP_RDSFDP       0x5a    /* Read SFDP */
 #define SPINOR_OP_RDCR         0x35    /* Read configuration register */
 #define SPINOR_OP_RDFSR                0x70    /* Read flag status register */
 
@@ -110,6 +113,9 @@
 /* Configuration Register bits. */
 #define CR_QUAD_EN_SPAN                BIT(1)  /* Spansion Quad I/O */
 
+/* Status Register 2 bits. */
+#define SR2_QUAD_EN_BIT7       BIT(7)
+
 
 /* Supported SPI protocols */
 enum spi_nor_protocol_class {
-- 
2.7.4

Reply via email to